A data center is one example of a computing environment that houses computer systems and various networking, storage and other related components. Many organizations and businesses operate and maintain data centers to provide computing and information services to support their day-to-day operations. Data centers may also provide computing services on a permanent or an as-needed basis to businesses and individuals as a remote computing service or to provide “platforms as a service” or “software as a service” (e.g., cloud computing). The computing resources provided by a data center may include various types of resources, such as data processing resources, data storage resources, data communication resources and the like. To facilitate increased utilization of data center resources, virtualization technologies may allow a single physical computing machine to host one or more instances of virtual machines (VMs) that appear and operate as independent computer machines to a remotely connected computer user. Customers of a data center may sometimes request changes to a virtual machine instance or request a particular configuration. The data center may also add new computing resources or update existing computing resources. The data center may confirm that such updates and changes meet performance criteria.